The air compressor industry has been substantially stagnant in new product development for the last five to ten years. The last product development in the field which can be considered "innovative" would be the oil-less compressors introduced in the mid 1980's. While a major quality difference exists among the major manufacturers, the compressors themselves are essentially indistinguishable from one another in appearance and function. In general, each prior art air compressor includes a three piece cylindrical tank, a motor mounted on a saddle which is welded to the tank, and an upwardly projecting cylinder with a piston rod connected at a lower end to an eccentric driven by the motor. The upper end of the cylinder has an exhaust port which is connected by hose or pipe to an intake port on the tank, to provide compressed air to the tank.
These prior art compressors suffer several drawbacks. First, the cylindrical three piece tank requires two separate welding operations to form the tank, and further requires that saddles and other attachment pieces be welded to the tank in order to mount the motor and other equipment on the tank. Thus, the tank can be labor intensive to manufacture.
A second problem with prior art compressors is in the orientation of the cylinder and piston rod. In order to create a low profile for the overall compressor, the piston rod is necessarily of short length, such that the upper exhaust end of the cylinder does not project above the motor housing any farther than absolutely necessary. While the shorter piston rod provides a lower compressor profile, it also results in greater angles of piston operation and reduced efficiency due to necessary head clearances.